feat(tracker): add product switcher — filter items by any product

- product-config.ts: add getRequestProductId(req) + KNOWN_PRODUCTS
- product-context.tsx: client-side product selection context
- product-switcher.tsx: native select dropdown component
- tracker-client.ts: inject x-product-id header on all API calls
- proxy route: forward x-product-id header to platform-service
- providers.tsx: wrap with ProductProvider
- dashboard/layout.tsx: render ProductSwitcher in top nav

dashboards/tracker-web/src/app/api/tracker/[...path]/route.ts

@@ -28,6 +28,10 @@ async function proxy(req: NextRequest, { params }: { params: Promise<{ path: str
       headers['Authorization'] = `Bearer ${tokenHeader}`;
     }
 
+    // Forward product switcher header so platform-service filters by product
+    const productId = req.headers.get('x-product-id');
+    if (productId) headers['x-product-id'] = productId;
+
     const fetchOptions: RequestInit = {
       method: req.method,
       headers,

dashboards/tracker-web/src/app/dashboard/layout.tsx

@@ -4,6 +4,7 @@ import { useEffect } from 'react';
 import { useRouter } from 'next/navigation';
 import Link from 'next/link';
 import { useAuth } from '@/lib/auth-context';
+import { ProductSwitcher } from '@/components/product-switcher';
 
 const NAV_ITEMS = [
   { href: '/dashboard', label: 'Overview' },
@@ -51,6 +52,7 @@ export default function DashboardLayout({ children }: { children: React.ReactNod
             </nav>
           </div>
           <div className="flex items-center gap-4">
+            <ProductSwitcher />
             <span className="text-sm text-muted-foreground">{user.email}</span>
             <button
               onClick={logout}

dashboards/tracker-web/src/app/providers.tsx

@@ -3,6 +3,7 @@
 import { useEffect, type ReactNode } from 'react';
 import { AuthProvider } from '@/lib/auth-context';
 import { ThemeProvider } from '@/lib/theme-context';
+import { ProductProvider } from '@/lib/product-context';
 import { initTelemetry } from '@/lib/telemetry';
 
 import { CSPostHogProvider } from '@/components/posthog-provider';
@@ -15,7 +16,9 @@ export function Providers({ children }: { children: ReactNode }) {
   return (
     <CSPostHogProvider>
       <ThemeProvider>
-        <AuthProvider>{children}</AuthProvider>
+        <ProductProvider>
+          <AuthProvider>{children}</AuthProvider>
+        </ProductProvider>
       </ThemeProvider>
     </CSPostHogProvider>
   );

dashboards/tracker-web/src/components/product-switcher.tsx

@@ -0,0 +1,22 @@
+'use client';
+
+import { useProduct } from '@/lib/product-context';
+
+export function ProductSwitcher() {
+  const { productId, setProductId, products } = useProduct();
+
+  return (
+    <select
+      value={productId}
+      onChange={e => setProductId(e.target.value)}
+      className="h-8 rounded-md border border-border bg-card px-2 text-sm font-medium text-foreground focus:outline-none focus:ring-2 focus:ring-ring"
+      aria-label="Select product"
+    >
+      {products.map(p => (
+        <option key={p.id} value={p.id}>
+          {p.name}
+        </option>
+      ))}
+    </select>
+  );
+}

dashboards/tracker-web/src/lib/product-config.ts

@@ -6,6 +6,7 @@
  */
 
 import { loadProductIdentity } from '@bytelyst/config';
+import type { NextRequest } from 'next/server';
 
 const identity = loadProductIdentity();
 
@@ -13,3 +14,19 @@ export const PRODUCT_ID = identity.productId;
 export const DISPLAY_NAME = identity.displayName;
 export const LICENSE_PREFIX = identity.licensePrefix;
 export const PACKAGE_NAME = identity.packageName;
+
+/**
+ * Extract productId from request header (set by client-side product switcher),
+ * falling back to the env-based PRODUCT_ID.
+ */
+export function getRequestProductId(req: NextRequest): string {
+  return req.headers.get('x-product-id') || PRODUCT_ID;
+}
+
+/** All known products in the ByteLyst ecosystem. */
+export const KNOWN_PRODUCTS = [
+  { id: 'lysnrai', name: 'LysnrAI', icon: 'Mic' },
+  { id: 'chronomind', name: 'ChronoMind', icon: 'Clock' },
+  { id: 'nomgap', name: 'NomGap', icon: 'Apple' },
+  { id: 'mindlyst', name: 'MindLyst', icon: 'Brain' },
+] as const;

dashboards/tracker-web/src/lib/product-context.tsx

@@ -0,0 +1,48 @@
+'use client';
+
+import { createContext, useContext, useState, useCallback, type ReactNode } from 'react';
+import { KNOWN_PRODUCTS, PRODUCT_ID } from '@/lib/product-config';
+
+const STORAGE_KEY = 'tracker_selected_product';
+
+interface ProductContextValue {
+  productId: string;
+  productName: string;
+  setProductId: (id: string) => void;
+  products: typeof KNOWN_PRODUCTS;
+}
+
+const ProductContext = createContext<ProductContextValue | null>(null);
+
+function getInitialProduct(): string {
+  if (typeof window === 'undefined') return PRODUCT_ID;
+  return localStorage.getItem(STORAGE_KEY) || PRODUCT_ID;
+}
+
+export function ProductProvider({ children }: { children: ReactNode }) {
+  const [productId, setProductIdState] = useState<string>(getInitialProduct);
+
+  const setProductId = useCallback((id: string) => {
+    setProductIdState(id);
+    if (typeof window !== 'undefined') {
+      localStorage.setItem(STORAGE_KEY, id);
+    }
+  }, []);
+
+  const product = KNOWN_PRODUCTS.find(p => p.id === productId);
+  const productName = product?.name ?? productId;
+
+  return (
+    <ProductContext.Provider
+      value={{ productId, productName, setProductId, products: KNOWN_PRODUCTS }}
+    >
+      {children}
+    </ProductContext.Provider>
+  );
+}
+
+export function useProduct(): ProductContextValue {
+  const ctx = useContext(ProductContext);
+  if (!ctx) throw new Error('useProduct must be used within <ProductProvider>');
+  return ctx;
+}

dashboards/tracker-web/src/lib/tracker-client.ts

@@ -57,7 +57,18 @@ const trackerApi = createApiClient({
   getToken: () => (typeof window !== 'undefined' ? localStorage.getItem('tracker_token') : null),
 });
 
-const apiFetch = trackerApi.fetch;
+/** Wrap apiFetch to inject x-product-id header from localStorage. */
+function apiFetch<T>(path: string, options?: RequestInit): Promise<T> {
+  const extra: Record<string, string> = {};
+  if (typeof window !== 'undefined') {
+    const pid = localStorage.getItem('tracker_selected_product');
+    if (pid) extra['x-product-id'] = pid;
+  }
+  return trackerApi.fetch<T>(path, {
+    ...options,
+    headers: { ...extra, ...(options?.headers as Record<string, string>) },
+  });
+}
 
 export async function listItems(params?: Record<string, string>): Promise<ListItemsResponse> {
   const qs = params ? `?${new URLSearchParams(params).toString()}` : '';